#!/usr/bin/env python
#coding=utf-8
#filename=2-9a

#while循环和操作符,求平均值

a = [1,2,3,4,6]
b = 0
c = 0

while b < 5:
    c = c + a[b]
    b = b + 1
    
c = float(c)
print c / 5

#updata

a = [1,2,3,4,6]
b = 0
c = 0

while b < 5:
    c = c + a[b]
    b = b + 1
    
print float(c) / 5
